The present invention relates to the general field of blades for a turbojet fan. The invention relates more particularly to their shape.
The preparation of a turbojet fan blade needs to satisfy various multidisciplinary criteria. A fan blade is designed so as to optimize its efficiency and its thrust (in particular its flow rate capacities at high speed) while guaranteeing it has good mechanical strength, in particular at high speeds of rotation at which the mechanical stresses to which the blade is subjected are the most severe. The design of a fan blade must also comply with noise targets defined at various operating points described in current standards.
Numerous fan blade shapes have been proposed. They are generally characterized by a stacking relationship for the leading edges of their profiles and by the variation in the sweep angle of the leading edge in order to improve the aerodynamic performance of the blade and in order to reduce the noise generated by the fan. By way of example, mention may be made of publication EP 1 452 741, which describes a particular swept blade shape for a turbojet fan or compressor.